The present invention relates generally to an ultrasonic measuring apparatus, and more particularly to an ultrasonic diagnostic apparatus for detecting variations of an acoustic characteristic to obtain the fluctuation of temperature within a body to be examined.
The need to measure a temperature within the body of a patient is currently known, for example, in thermotherapy for cancer. Various acoustic characteristics of the tissue within the body depends upon temperature and are extremely important measuring items in diagnostics. A method of measuring the fluctuation of temperature within the body using the fact where acoustic velocity being one of the acoustic characteristics depends upon temperature is disclosed as intersection beam method in "The 45 Issue of Lecture Paper of Study Meeting of Ultrasonic Medical Society (pages 21 to 22) published in 1984.
However, such a method does not produce satisfactory results for meeting requirements in terms of accurately measuring the fluctuation of temperature even if the acoustic velocity varies depending on tissues of the body.